绝经状态、口服避孕药和绝经后激素治疗对正常乳腺实质动态MRI时血流动力学的影响

目的研究乳腺MR成像时,绝经状态、口服避孕药和绝经后激素治疗对正常乳腺实质的对比增强和非肿物性强化区的影响。方法共459名女性志愿者[平均年龄(49.1±12.5)岁]在注射钆对比剂后的1～5min进行乳腺的三维T1加权MR成像。通过划定感兴趣区对正常乳腺实质进行定量分析,并计算增强百分率。对非肿物性强化区进行半定量分析,采用5条预先设定的血流动力学曲线来描述信号强度的变化特点。采用随机效应模型分析口服避孕药(n=69)和绝经后激素治疗(n=24)对于对比增强的影响。结果绝经前妇女乳腺实质的强化明显高于绝经后妇女(P<0.001)。口服避孕药使对比增强明显降低(P=0.01),而绝经后激素治疗的影响却很小(P=0.52)。非肿物性强化的血流动力学曲线与绝经前和绝经后妇女有着明显的差异(P<0.0001),但是口服避孕药和非避孕药使用者之间却有相似表现(P=0.61),绝经后激素治疗和非激素治疗者也是如此(P=0.77)。结论正常乳腺实质的强化和非肿物性强化区明显受绝经状态的影响,但它们不受绝经后激素治疗的影响,仅受口服避孕药的中度影响。     

Influence of menopausal status and use of hormone replacement therapy on radiation dose from mammography in routine breast screening

Menopausal status and hormone replacement therapy (HRT) cause alterations in breast structure which can affect mammographic image quality. Here we present the results of a study to discover the effect of menopausal status and HRT use on breast dose. Women attending routine screening completed questionnaires which included questions regarding menopausal status and HRT use. Details of the radiographic technique factors were recorded, from which the mean glandular dose (MGD) per film for each woman was calculated. MGD values were analysed with regard to the woman's menopausal status and HRT use. The data from 516 women were analysed. Among the women who had never used HRT, women who had not undergone the menopause had a mean MGD of 2.94 mGy per film, whereas post-menopausal women had a lower mean MGD of 2.52 mGy per film: a difference which was found to be highly significant (p = 0.0045). Post-menopausal women who had never used HRT and those who had previously used HRT, but had ceased using it, had identical mean MGDs (2.54 mGy per film), whereas current HRT users had a significantly greater mean MGD (2.89 mGy per film, p = 0.003). Women currently using HRT receive a statistically significantly larger radiation dose from routine breast screening than other women. However, this effect is small and only occurs during the period of HRT use. Women who have ceased using HRT show no difference in MGD compared with women who have never taken HRT.     

Correlation between breast density in mammography and background enhancement in MR mammography

Purpose

We aimed to analyse the influence of mammographic breast density on background enhancement (BE) at magnetic resonance (MR) mammography in preand postmenopausal women. In addition, we questioned predictability of contrast-enhancement dynamics of normal fibroglandular tissue (NFT) at MR mammography according to mammographic breast density.

Materials and methods

Twenty-six patients (mean age 51.54±11.5 years; range 37–79 years) who underwent both MR mammography and conventional mammography were included in this retrospective study. Fourteen patients were premenopausal and 12 were postmenopausal. The ethics committee of our institution approved the study. The mammograms were retrospectively reviewed for overall breast density according to the four-point scale (I–IV) of the Breast Imaging Reporting and Data System (BI-RADS) classification. Two radiologists, who were unaware of the clinical data, separately assessed the MR mammography images. Images were assessed for enhancement kinetic features (enhancement kinetic curve and the early-phase enhancement rate) and BE. MR mammography and conventional mammography findings were compared according to BI-RADS breast density category and menopausal status.

Results

Percentage of increased signal intensity values during the first minute did not change according to mammographic breast density, and the mean early-phase enhancement rate scores were similar among breast density groups (p=0.942). There was no significant difference between pre- and postmenopausal groups. Enhancement kinetic features of the different groups based on BI-RADS breast density category and menopausal status were similar. There was no correlation between breast density and BE in either premenopausal (p=0.211) or in postmenopausal (p=0.735) groups.

Conclusions

We determined no correlation between mammographic breast density and so-called BE in MR mammography in either premenopausal or postmenopausal women. NFT at MR mammography cannot be predicted on the basis of mammographic breast density.     

Contrast kinetics of the malignant breast tumour--border versus centre enhancement on dynamic midfield MRI

PURPOSE: To quantify the border versus centre enhancement of malignant breast tumours on dynamic magnetic resonance mammography. MATERIALS AND METHODS: Fifty-two women diagnosed with primary breast cancer underwent dynamic magnetic resonance mammography (Omniscan 0.2 mmol/kg bodyweight) on a midfield scanner (0.6 T), prior to surgery. The following five variables were recorded from the border and centre regions of the tumours: Early Enhancement, Time to Peak, Wash-in rate, Wash-out rate and Area under Curve. Information on histology type, oestrogen and progesterone receptor status was collected. Statistical analysis was performed in SAS 9.1 as paired samples t-tests. RESULTS: Fifty of 52 malignant tumours displayed a faster Early Enhancement in the border region compared to the centre (p<0.0001). Significant differences between the border and centre values were found for Time to Peak, Wash-in rate, Wash-out rate and Area under Curve. Hormone receptor positive tumours displayed an over-all highly significant difference between border and centre enhancement, whereas no significant differences for any of the five variables were recorded in neither oestrogen nor progesterone hormone receptor negative tumours. CONCLUSION: The border/centre enhancement difference in malignant breast tumours is easily visualized on midfield dynamic magnetic resonance mammography. The dynamic behaviour is significantly correlated to histological features and receptor status of the tumours.     

Usefulness of dynamic MR mammography for diagnosis of axillary lymph node status in breast cancer patient

A retrospective study was performed to evaluate whether dynamic MR imaging is useful for the diagnosis of axillary lymph node metastases from breast cancer. Thirty-five patients with breast cancer were scanned and 147 lymph nodes were detected and compared with pathological nodal status. The parameters were the long axis dimension, the short axis dimension, the long-to-short axis (L/S) ratio, the shape, the contrast enhancement ratio (CER), the CER of lymph node-to-primary tumor (L/P) ratio. All parameters had significant differences between metastatic and normal nodes and there was a positive correlation between the CER of primary breast tumors and metastatic nodes. Multivariate analysis identified three parameters: the shape, the CER (1st phase), the L/P ratio (1st phase). ROC analysis revealed the shape and CER are superior in diagnostic performance to L/P ratio. If the shape and CER (1st phase) 60% and above are employed as criteria, the sensitivity, the specificity, the accuracy and the positive and negative predictive value were 86.0%, 78.4%, 81.0%, 67.2% and 91.6%, respectively. This method gives us useful information about the evaluation of axillary lymph node status preoperatively.     

Background enhancement in breast MR: Correlation with breast density in mammography and background echotexture in ultrasound

Objective

This study aimed to determine whether background enhancement on MR was related to mammographic breast density or ultrasonographic background echotexture in premenopausal and postmenopausal women.

Materials and methods

We studied 142 patients (79 premenopausal, 63 postmenopausal) who underwent mammography, ultrasonography, and breast MR. We reviewed the mammography for overall breast density of the contralateral normal breast according to the four-point scale of the BI-RADS classification. Ultrasound findings were classified as homogeneous or heterogeneous background echotexture according to the BI-RADS lexicon. We rated background enhancement on a contralateral breast MR into four categories based on subtraction images: absent, mild, moderate, and marked. All imaging findings were interpreted independently by two readers without knowledge of menstrual status, imaging findings of other modalities.

Results

There were significant differences between the premenopausal and postmenopausal group in distribution of mammographic breast density, ultrasonographic background echotexture, and degree of background enhancement. Regarding the relationship between mammographic density and background enhancement, there was no significant correlation. There was significant relationship between ultrasonographic background echotexture and background enhancement in both premenopausal and postmenopausal groups.

Conclusion

There is a significant correlation between ultrasonographic background echotexture and background enhancement in MR regardless of menopausal status. Interpreting breast MR, or scheduling for breast MR of women showing heterogeneous background echotexture needs more caution.     

Correlation between enhancement characteristics of MR mammography and capillary density of breast lesions

ObjectiveTo correlate capillary density of breast lesions using the markers D2-40, CD31, and CD34 with early and late enhancement of magnetic resonance mammography (MRM).Materials and methodsThe local ethics committee approved this study, and informed consent was available from all patients. The study included 64 women with 66 histologically proven breast lesions (41 malignant, 25 benign). MR-enhancement 1 min after contrast medium administration was determined in the tumor (I_t1/I_t0 ratio) and in comparison to the surrounding tissue (I_t1/I_t1-fat ratio). Capillary density was quantified based on immunohistological staining with D2-40, CD31, and CD34 in breast tumors and surrounding breast tissue. Mean capillary densities were correlated with contrast enhancement in the tumor and surrounding breast tissue. The Kruskal–Wallis test was used to test whether lesions with different MR enhancement patterns differed in terms of capillary density.ResultsFor CD34, there was statistically significant correlation between capillary density and tumor enhancement (r = 0.329, p = 0.012), however not for the malignant or benign groups separately. Mean vessel number identified by staining with D2-40 and CD31 did not correlate significantly with tumor enhancement (D2-40: r = −0.188, p = 0.130; CD31: r = 0.095, p = 0.448). There were no statistically significant differences in capillary density between breast lesions with delayed enhancement or a plateau and lesions showing washout (Kruskal–Wallis test. D2-40: p = 0.173; CD31: p = 0.647; CD34: p = 0.515).ConclusionOf the three markers tested, CD34 showed best correlation between early contrast enhancement on MRM and capillary density. Further studies are necessary to clearly demonstrate an association between capillary density and contrast enhancement in breast tumors and surrounding tissue.     

MR imaging of the breast with Gd-DTPA enhancement: comparison with mammography and ultrasonography.

The accuracy of MR imaging with Gd-DTPA enhancement was compared with mammography and ultrasonography in 52 patients with clinically palpable benign and malignant breast masses (36 carcinomas, 2 malignant phyllodes tumors, 7 fibroadenomas, 7 cysts). On dynamic MR imaging, carcinomas and fibroadenomas were discriminated by their different dynamic enhancement profiles. In carcinomas, signal intensity increased rapidly, reaching a peak or plateau within 2 min after the injection of contrast medium. In fibroadenomas, signal intensity showed a much slower continuous increase without ceasing until about 8 min after injection. Malignant phyllodes tumors showed a dynamic enhancement profile identical to that of benign fibroadenomas. MR imaging correctly identified 84% of malignant tumors, 86% of fibroadenomas, and 100% of cysts, and was substantially more accurate in tissue characterization than mammography. The results of ultrasonography were highly similar to those of MR imaging. However, no single modality was infallible, and the three modalities were complementary rather than competitive. Considering the high cost and long examination time of MR imaging, mammography supplemented by ultrasonography seems to be the method of choice in the diagnosis of breast lesions. Nevertheless, MR imaging can add important information when the results of mammography and ultrasonography are insufficient or contradictory.     

MR mammography: influence of menstrual cycle on the dynamic contrast enhancement of fibrocystic disease

Magnetic resonance mammography (MRM) provides data regarding the nature of tumours based on contrast medium dynamics; fibrocystic changes in the breast, however, may lead to false-positive results. This study investigated whether the contrast medium dynamics of fibrocystic changes are dependent on the menstrual cycle. Twenty-four patients with palpable lumps but normal mammographies and ultrasound studies were examined. The MRM technique was performed during the first and second part of the menstrual cycle using a FLASH 3D sequence, both native and at 1, 2, 3 and 8 min after intravenous application of 0.15 mmol/kg body weight of gadodiamide. The calculated time–intensity curves were evaluated based on the following criteria: early percentage of contrast medium uptake in relation to the native value; formation of a plateau phenomenon after the second minute; the point of maximal contrast medium uptake; and calculation of the contrast enhancing index. During the second half of the menstrual cycle, a generally greater contrast medium uptake was observed. Nevertheless, when further diagnostic criteria, such as continuous contrast medium increase as a function of time, were considered, there was no increased rate of false-positive findings. The phase of the menstrual cycle may affect the specificity of the examination, if only the quantitative contrast medium uptake and the percentage of contrast medium uptake in the first 2 min are considered. A control MRM during the other half of the cycle may then be indicated and additional diagnostic criteria may improve specificity. Received: 14 August 1997; Revision received: 5 December 1997; Accepted: 5 October 1998     

Comparison of lesion size estimated by dynamic MR imaging,mammography and histopathology in breast neoplasms

To evaluate the accordance of size measurements of malignant breast lesions 65 women with 76 malignant lesions were preoperatively examined with triple diagnosis (mammography was performed in three views with additional views if necessary) and dynamic MR imaging using a subtraction technique with a 3D T1-weighted sequence. Maximum lesion size at histopathology was used as gold standard and compared with maximum lesion size at MRI and mammography. All measurements were made independently for each method. Histopathology verified 48 invasive, 5 in situ, and 23 mixed lesions. No significant difference was found for the pure invasive lesions (p=0.366). In the mixed lesions a slightly better result for MRI was indicated (p=0.116), although there was a great spread. Only five pure in situ lesions were assessed, too few to draw any statistical conclusions (p>0.5). An overall difference indicated a slight superiority of MRI (p=0.097). The MR imaging and mammography are both good at measuring the size of detected invasive breast malignancies. The total sizes of mixed lesions are frequently underestimated by both MRI and mammography, although the invasive parts were equally well described and measured with both methods. Electronic Publication     

绝经状态对于乳腺MRI中背景实质强化和纤维腺组织的影响

目的评价绝经状态对于乳腺MRI中背景实质增强和纤维腺组织数量的影响。方法回顾性研究2010年7月—11月进行乳腺MRI筛查的1130名妇女。这些妇女中有28名在绝经前和绝经后的一个时间点均进行了乳腺MR检查(中位数间隔49个月)。2位独立的阅片者对绝经状态采用盲法评价背景实质的强化(极少/轻度/中度/明显)和纤维腺组织(脂肪性/散在/不均匀致密/致密)的情况。当存在意见分歧时需协商达成共识。采用符号检验来评价等级类别的变化,采用Spearman秩和检验和Fisher确切检验来分析不同变量间的相关性。结果大多数妇女在绝经后的乳腺MRI中表现为背景实质强化和纤维腺组织减少(P=0.0001和P=0.0009)。背景实质强化类型在39%(11/28)的妇女中没有变化,而在61%(17/28)的妇女表现为减低。纤维腺组织类型在61%(17/28)的妇女没有变化,而在39%(11/28)的妇女中表现为减少。年龄、绝经原因和进行MRI的间隔对背景实质强化和纤维腺组织均无明显影响。结论 MRI中,大多数妇女在绝经后背景实质强化和纤维腺组织表现减少,背景实质强化改变要比纤维腺组织明显。     

Impact of menopausal status on background parenchymal enhancement and fibroglandular tissue on breast MRI

Objective

To evaluate the effect of menopausal status on the background parenchymal enhancement (BPE) and amount of fibroglandular tissue (FGT) on breast MRI.

Methods

Retrospective review identified 1,130 women who underwent screening breast MRI between July and November 2010. In 28 of these women, breast MRI was performed both at one time point while pre- and one time point while post-menopausal (median interval 49?months). Two independent readers blinded to menopausal status used categorical scales to rate BPE (minimal/mild/moderate/marked) and FGT (fatty/scattered/heterogeneously dense/dense). Consensus was reached when there was disagreement. The sign test was used to assess changes in rating categories, and the Spearman rank and Fisher’s exact tests were used to measure correlations and associations between variables.

Results

Significant proportions of women demonstrated decreases in BPE and FGT on post-menopausal breast MRI (P?=?0.0001 and P?=?0.0009). BPE category was unchanged in 39?% (11/28) and decreased in 61?% (17/28) of women. FGT category was unchanged in 61?% (17/28) and decreased in 39?% (11/28) of women. Age, reason for menopause, or interval between MRIs had no significant impact on changes in BPE and FGT.

Conclusion

On MRI, BPE, and FGT decrease after menopause in significant proportions of women; BPE decreases more than FGT.

Key Points

? On MRI, background parenchymal enhancement and fibroglandular tissue both decrease after menopause. ? The reduced postmenopausal enhancement is more marked in parenchyma than fibroglandular tissue. ? Background enhancement and fibroglandular tissue seen on MRI are under hormonal influence.     

MRI乳腺非肿块样强化灶:乳腺摄影及乳腺超声对病变分类的额外价值

目的评价常规乳腺影像检查方法(乳腺摄影及超声)对判断MRI非肿块样强化灶是否为恶性病变的附加诊断价值,建立一套联合多种乳腺影像检查手段评价乳腺病变的模式。材料与方法本研究经伦理委员会批准并豁免病人的知情同意。共分析115例女性(年龄21～76岁,平均48.3     

Pharmacokinetic analysis of ductal carcinoma in situ of the breast using dynamic MR mammography

The purpose of this study was to assess the relationship between functional parameters derived from dynamic MR imaging and the histological findings of breast ductal carcinoma in situ (DCIS) and DCIS with invasive foci, and to evaluate whether these parameters might predict DCIS patient outcome. Two parameters, amplitude A and k₂₁, were determined from multicompartmental pharmacokinetic analyses of dynamic MR mammography in 39 patients with needle biopsy-proven primary DCIS. After surgery, the histological tumor characteristics, including microvessel density (MVD) (anti-CD-34), vascular permeability (anti-VEGF antigen) and histological grade, were evaluated. Histology revealed 27 pure DCIS and 12 DCIS with invasive foci. In pure DCIS, positive correlations between MVD and amplitude A (r=0.56, P<0.0025) and between MVD and k₂₁ (r=0.43, P=0.02) were found. As for histological grade, the differences in both functional parameters of grade 1 versus grade 2 and grade 1 versus grades 2 and 3 combined were significant (P<0.05). No significance was found in the analysis of DCIS with invasive foci. Our results indicated that functional MRI-based parameters might possess the potential to predict the outcome of patients with DCIS. Further study will be needed with larger series over longer periods.     

Gd-EOB-DTPA-enhanced MR imaging: evaluation of hepatic enhancement effects in normal and cirrhotic livers

Objective

The purpose of this study was to assess differences in enhancement effects of liver parenchyma between normal and cirrhotic livers on contrast-enhanced MR imaging (CE-MRI) obtained with Gd-EOB-DTPA.

Methods

A total of 99 patients with cirrhotic liver (n = 58; Child-Pugh class A, n = 30; B, n = 22; C, n = 6) and normal liver (n = 41) underwent Gd-EOB-DTPA-enhanced MR imaging. CE images were obtained before contrast injection, in the arterial phase (AP) at 25 s or modified scan delay, in the portal phase (PP) at 70 s, in the equilibrium phase (EP) at 3 min, and in the hepatobiliary phase (HP) at 3 times (10, 15 and 20 min). Signal intensity of the liver in all phases was defined using region-of-interest measurements for relative enhancement (RE) calculation.

Results

In normal-liver and Child-Pugh class A and B patients, mean RE of liver parenchyma increased significantly (P < 0.03–0.001) with time until 20-min HP. Conversely, mean RE for Child-Pugh class C patients did not show any increasing tendency after PP. Mean RE of liver parenchyma at EP and HP (10-, 15- and 20-min) was highest in normal liver, followed by Child-Pugh class A, B and C cirrhosis (P < 0.02–0.001).

Conclusion

Hepatic parenchymal enhancement on CE-MR images obtained using Gd-EOB-DTPA is affected by the severity of cirrhosis.     

Overall breast density in MR mammography: diagnostic and therapeutic implications in breast cancer

The objective of this study was to assess the efficacy of MR mammography (MRM) in evaluating breast cancer extent in women with fatty or dense breasts, and its contribution to the therapeutic approach. The authors reviewed 97 carcinomas detected in 93 women (both symptomatic and from screening) that were classified in two groups according to breast density pattern. Mammography, ultrasound (US), and MRM were performed to evaluate size, extension of the in situ component, presence of multifocal/multicentric disease, and contralateral involvement. Results obtained on mammography plus US were balanced against MRM, considering pathologic analysis as the gold standard. For fatty breasts (n=47), exact measurement was found on mammography plus US and on MRM alone in 70%, underestimation on mammography plus US 23.5% and on MRM 11% (P=0.005). For dense breasts (n=50), exact measurement was found on mammography plus US in 40% and on MRM alone 68%, underestimation on mammography plus US 52% and on MRM 10% (P=0.005). Overall, good correlation (R>0.71) was found between pathologic and clinical size with all imaging methods; nevertheless, when evaluating multifocal/multicentric disease, a poor correlation was observed between histologic assessment and mammography plus US (R=0.52), but it was excellent with regard to MRM (R=0.99). In fatty breasts, the combination of mammography and US allows for a precise assessment of tumoral extension. However, these results show that in dense breasts, MRM is superior to mammography plus US, suggesting that its systematic use in this group of patients is justifiable.     

Non-mass-like enhancement on contrast-enhanced breast MR imaging: Lesion characterization using combination of dynamic contrast-enhanced and diffusion-weighted MR images

Purpose

To evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in characterization of lesions showing non-mass-like enhancement on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy.

Materials and methods

We analyzed consecutive MR images in 45 lesions showing non-mass like enhancement in 41 patients. We analyzed lesion size, distribution, internal enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators for malignancy. In a validation study, 22 non-mass-like enhancement lesions in 21 patients were examined. We calculated diagnostic accuracy when we presume category 4b, 4c, and 5 lesions as malignant or high to moderate suspicion for malignancy, and category 4a and 3 as low suspicion for malignancy or benign.

Results

Segmental distribution (P = 0.018), clumped internal enhancement (P = 0.005), and ADC less than 1.3 × 10⁻³ mm²/s (P = 0.047) were the strongest MR indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87% (13/15), 86% (6/7), 93% (13/14), 75% (6/8) and 86% (19/22), respectively.

Conclusion

The combination of DCE-MRI and DWI showed high diagnostic accuracy in characterization of non-mass-like enhancement lesions on breast MR images.